The invention relates generally to cooling system pressure testing devices, and more specifically to an apparatus for monitoring the internal pressure and preferably temperature of a cooling system that uses liquid coolant to facilitate temperature reduction.
Engines, such as those in motorcycles, automobiles, and other motive vehicles, typically utilize coolant systems with liquid coolant to facilitate temperature reduction. A variety of potential problems are associated with such cooling systems. In order to diagnose these problems, it is useful to measure the pressure of the cooling system, as well as the temperature of the coolant itself, during a running cycle. In this regard, it is further advantageous for the system to have the capability to pressurize the cooling system in order to obtain these readings and locate any leaks in the system. Various apparatus are known for testing such systems by pressurization in order to detect leaks therein. Each of these apparatus, however, has shortcoming in either design or operation.
U.S. Pat. No. 1,776,170 to Thimblethorpe discloses a cap-like device that fits over the opening of a radiator and includes a temperature sensor and a level sensor for indicating the level and temperature of the liquid in the radiator of an automotive vehicle.
U.S. Pat. No. 3,255,631 to Franks discloses a pressure/temperature indicating apparatus attached to a radiator cap with a sealing mechanism. The sealing mechanism includes a spring that bears against a metal washer, serving to seal the radiator with a rubber washer.
U.S. Pat. No. 3,100,391 to Mansfield discloses a pressure and temperature indicator that is adapted to fit over a radiator cap of an automotive cooling system. The radiator cooling system may be pressurized using a pump or a valve stem and pressurized air.
U.S. Pat. No. 4,702,620 to Ford discloses an electronic thermostat having a temperature sensor, which is inserted through a cap-like device adapted to fit over the opening of the radiator. The system is designed to monitor the temperature of the coolant and the radiator over time.
U.S. Pat. No. 5,324,114 to Vinci discloses a device for monitoring temperature and pressure of a liquid coolant in a cooling system. Vinci includes a particularized sealant that seals around the probes of a needle from a temperature or pressure probe and reseals itself upon removal of the needle.
U.S. Pat. No. 5,557,966 to Corry and U.S. Pat. No. 5,760,296 to Wilson disclose cooling system pressure testing devices that utilize bladders that may be inserted into an inlet in a deflated state and then inflated to couple the device to the inlet.
Systems available in the market typically include a pressure probe assembly and a plurality of adapter cap fittings designed to suit a variety of radiator neck configurations and sizes. Typically, such test systems require 25-30 different fittings in order to provide a system that may be utilized with the broad range of vehicles on the market. In use, an appropriately sized adapter cap fitting is selected to fit the radiator neck size and configuration of the cooling system being tested. The cap fitting is secured to the neck of the radiator, and a pressure probe and gas compressor coupled to the cap fitting. A typical pressure probe includes a pressure gauge, and has an outlet connectable to a selected one of the adapter cap fittings, the fitting also being adapted to receive pressurized gas from a compressor. The cooling system is then pressurized and the pressure measured.
Kits of this type are typically expensive and complex as they consist of a large number of parts, usually including a plurality of adapter cap fittings. Further, the range of cap fittings available generally does not cover all possible radiator neck configurations and sizes. Additionally, as these cap fittings are loose parts of a kit, they are often lost or misplaced.
Another attempt to simplify pressure-testing devices is the Uni-Cap Universal Cap Adapter, in which a single-size pressure probe adapter cup is permanently affixed to an expandable radiator orifice fitting. Although fitting a wide range of radiator necks, the principal disadvantage of the Uni-Cap device is that it can only be used with specific commercially available pressure probe assemblies sized to mate with the permanently affixed adapter cup. This limitation reduces the flexibility of the Uni-Cap device, particularly with respect to pressure probes that do not fit the permanently affixed adapter cup. Therefore, a need exists for a truly cooling system orifice adapter that fits a wide range of radiator necks and is not limited by commercially available pressure probes.
Another disadvantage of the Uni-Cap design is the difficulty in repair or replacement of its components. Since the radiator cup is welded or brazed to the internal shaft, the Uni-Cap cannot be disassembled, or its components replaced without damaging the device. The universal radiator orifice fitting, for example, cannot be replaced if damaged by scale build-up in the radiator neck, improper installation, or general wear and tear. Ultimately, if any component of the Uni-Cap is damaged, the entire assembly must be rebuilt or replaced. Both alternatives are generally more costly than component replacement.
Other universal-type adapters are marketed by companies such as Autotestgerate Leitenberger GmbH, which markets adapters which similarly include a tapered rubber plug. One such device, which includes a conical rubber plug, is disclosed, for example, in German Application DE 32 30 146 A1. Other devices marketed by Autotestgerate Leitenberger GmbH include a stepped rubber plug, or a conical plug having a plurality of spaced, thin rings encircling the cone and distributed along the length of the cone. Autotestgerate Leitenberger GmbH also markets a universal-type device which includes a cylindrical plug which seats along an inner surface of the radiator to seal the device to the radiator. The latter device also includes a pair of brackets which clamp around surfaces of the radiator orifice. Similar devices are marketed by at least one Taiwanese company.
In view of the generally conical or straight cylindrical structure of each of the devices, however, even when properly placed on a vehicle, the plug of the adapter can be ejected from the radiator opening when high pressures are developed within the radiator. Such forcible ejection not only prevents proper testing of the vehicle, it can also be extremely dangerous, causing damage to both the vehicle and the user.
An object of the present invention is to provide a diagnostic tool for measuring cooling system temperature and/or pressure, such that the tool may be conveniently utilized in a variety of applications without requiring assembly or disassembly of the diagnostic tool itself. A related object of the invention is to provide such a diagnostic tool that may be utilized to apply pressurized gas from a hand pump or the like, or directly from a shop source.
Another object of the invention is to provide a modular universal pressure and temperature diagnostic tool that affords easy repair and replacement of parts that are susceptible to damage and heavy wear during normal use.
A further object of the invention is to provide a single adapter that may be utilized in a broad range of vehicle applications, eliminating the need for multiple adapters in standard testing systems.
A related object is to provide an adapter which can be directly connected to standard testing systems currently available on the market, but that is not limited to use with standard testing systems or a single radiator cup size.
A collateral object of the invention is to provide a device that may be efficiently manufactured and repaired at a relatively low cost.
Another important object is to provide a device that can consistently be safely used without collateral damage to the vehicle, other property, observers or the user. It is a more specific object to provide such a device which will not be ejected from the cooling system orifice during high pressure use.
The present invention overcomes the disadvantages of the prior art. These and other objects and advantages of the present invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.
The invention provides a modular cooling system orifice adapter that may be utilized as a diagnostic tool for evaluating a cooling system. In one embodiment, the device includes a relatively standard size orifice cup which is adapted to mate with a number of pressure testers available on the market. In another embodiment, the adapter includes a valve assembly having a shuttle valve that may be coupled to a source of pressurized gas, preferably a hand held pump. The shuttle valve is slidably received within a valve body that is coupled to a hollow shaft that may be placed in fluid communication with the cooling system. The shuttle valve may be used to selectively apply compressed gas to the cooling system by moving the shuttle valve between an open position wherein the source of compressed gas is in fluid communication with the hollow shaft and therefore the cooling system, and a closed position wherein there is no such fluid communication.
The valve assembly also includes a pressure gauge, which is preferably coupled to the shuttle valve to measure the pressure of the system. A temperature gauge may also be coupled to the valve body such that it is in fluid communication with the hollow shaft for determining the temperature within the system.
The valve assembly or cup is preferably coupled to cooling system by a universal fitting, which allows the adapter to be utilized with many sizes and shapes of cooling system openings. The universal fitting, in the form of a rubber adapter, has an exterior surface that generally decreases in diameter, preferably consisting of a plurality of round steps. The hollow shaft extends through the universal fitting and includes an enlarged head that is disposed at the small end of the universal fitting. A plate is disposed along the shaft at the opposite end of the universal fitting as is a compression device that may be actuated to draw the head and plate toward one another so as to axially compress the universal fitting, in turn causing the steps to bulge and seal against the opening in the radiator or the like after the adapter is partially inserted into the opening. The upper edges of the substantially axially extending walls of the steps of the universal fitting are preferably angled radially inward to minimize any possibility of the fitting separating from the cooling system orifice. In this way, the lower edge of the vertical step protrudes further outward than the upper, such that sufficient interference is created to typically prevent the lower edge of the vertical step from separating from the cooling system orifice when it is axially compressed and a pressure applied to the cooling system.
Preferably, the adapter is modular such that it may be readily disassembled for replacement of worn out or damaged components. In this regard, the hollow shaft is preferably threaded at one end. In this way, a compression device, such as a threaded knob may be simply rotated along the shaft threads to axially compress the universal fitting. Additionally, the valve or cup assembly may be coupled to the device by threads that mate with the threaded end of the shaft. A seal or gasket disposed between the shaft and the valve assembly or cup provides a sealed connection between the interior valve assembly or cup and the hollow interior of the shaft. Those of skill in the art will appreciate that the invention so provides an adapter that may be utilized as a practical and economical diagnostic tool in a large number of applications.
It will further be appreciated that this modular arrangement may also be utilized with other pressure testing devices available on the market by including the standardized radiator cup assembly in place of the valve assembly. In this way, the invention provides a repairable, and therefore practical and economical alternative to the use of multiple adapters typically provided with standard pressure testing devices.
These and other features and advantages of the invention will be more readily apparent upon reading the following description of a preferred exemplary embodiment of the invention and upon reference to the accompanying drawings wherein: